EMX for OS/2 EMX is an environment for creating 32-bit programs for OS/2 and DOS including GCC and utilities.

IBM Software: Application Development IBM VisualAge delivers innovative and open solutions to professional programmers to rapidly exploit network middleware while developing, extending and managing scalable business and web applications.

Visual Prolog development tools Logic-programming development environment. GUIs and other programs developed with Visual Prolog are portable between OS/2 and Windows. Supports Linux and SCO console applications too.

VyperHelp by MekTek VyperHelp is an OS/2-based help editor and converter for IPF, WinHelp, RTF, HTMLHelp and HTML.

WDSibyl Open source Delphi-like Visual Development Environment for OS/2 and Windows.